DAC units or DAC integrated circuits (IC) are in common use. Typically, during operation, the DAC units receive serial data, such as commands, through a serial input channel. To indicate that serial data (which is comprised of a bit stream) is to be received, a synchronization or sync signal is used. This sync signal can indicate both the beginning and end of a bit stream through a transition of logic states (rising or falling edges). Some examples of prior art DACs or DAC units are as follows: European Patent No. 0518511; U.S. Pat. Nos. 5,235,602; 5,303,227; 6,703,961; 6,993,616; and the data sheet for the AD5025/45/65 and AD5530/31.